In this sort of flow rate measuring device or flow rate controller, a fluid resistance member is provided, and from pressures on an upstream side and downstream side of the fluid resistance member, a flow rate is calculated (in a semiconductor process or the like, in the case where pressure on a downstream side is low, such as the case where the downstream side is connected to a vacuum chamber, a flow rate can be accurately calculated only from pressure on an upstream side).
For this purpose, there is known a device in which, for example, one common body unit that is a manifold block inside which flow paths are formed is formed, and the body unit is attached and integrated with the fluid resistance member and a pressure sensor.
In order to more accurately calculate a flow rate, a temperature of fluid is also required. For example, in the case of a pressure sensor of a type using a resistive element, an electrical resistance value of the resistive element is changed depending on the temperature to give rise to an error in a measured value, and therefor by measuring temperature at the pressure sensor, more accurate pressure in which the error is corrected can be measured. Also, fluid temperature influences viscosity or the like, and therefore if the fluid temperature at the fluid resistance member is known, the flow rate can be more accurately calculated.
Accordingly, in the past, for example, as illustrated in FIG. 13, a temperature sensor is attached to the body unit, and the temperature indicated by the temperature sensor is regarded as the temperatures at the fluid resistance member and pressure sensors to calculate the flow rate.
On the other hand, under circumstances of recent years where downsizing and simplification of devices are required, an open-close valve or the like attached on a upstream side or downstream side of the flow rate measuring device or flow rate controller has been changed from a pneumatic type valve to an electromagnetic type valve, and arranged more closely.